Light bulb



FIG. 1 is a top view of a light bulb showing my new design;

FIG. 2 is a first side view thereof;

FIG. 3 is a second side view thereof;

FIG. 4 is a third side view thereof;

FIG. 5 is a fourth side view thereof; and,

FIG. 6 is a bottom view thereof.

The broken lines in the figures are for illustrative purposes only and form no part of the claimed design. 

CLAIM The ornamental design for a light bulb, as shown and described. 